Apple TV Face Time Widescreen question

Hi. New to the forum.
We just purchased a new GEN 4 32G Apple TV. Our intention is to Face Time with my son's family. We are planning on using it with my Iphone 5SE.
After everything is hooked up and running Face Time through the phone to the Apple TV we cannot get it to show widescreen on the TV. It will show as the long vertical picture but when you turn the phone sideways to horizontal the picture stays small.
Is there some thing we are missing or can do to get the landscape orientation to show widescreen on the TV?
Thanks. SJ